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  1. #1

    Heat Pump Electric Strips v Propane

    Good Day,

    We just moved into a home in Central Maryland with a Heat Pump w/ electric back-up strips. I have only ever had NG heat. There is no option for NG at the new house. My question is: Upgrade to new heat pump with electric strips, or make the investment to have a propane backup for low temps?

    Additional info:
    Currently no propane tank onsite.
    We would like to have a back-up generator (propane powered). Relize a 20kw generator would not power the strips..., but could power the propane backup.

    Current Electric Price: 9.037 cents/kwh
    Current Propane Price: $3.50/gal

    Any help is appreciated!

    Thank You!

  2. #2
    Join Date
    Mar 2006
    Location
    The South
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    1,976
    Doug/Julie

    You did not give any details on your existing system.

    However, strictly on a BTU basis, backup electric strip heat is much cheaper than propane heat from a 95% eff furnace.

    See below from fuel comparison calculator that should be used as a guide only.

    Cost per 100,000 btu of useable heat

    Electric baseboard: $2.39
    Propane: $4.03

    My idea is to leave existing system alone this winter and then evaluate in spring.

    Any idea of the HSPF eff of existing heat pump?
    Size of existing heat strip? Are they staged?

    Post back.

    IMO

  3. #3
    Join Date
    Jan 2009
    Location
    Keokuk, IA
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    5,520
    Where I live, the cost of electric is closer to $3.80/100kBTU. According to a we search, in my area residential propane is just under $2/gallon. So 91.6kBTU's per gallon.. so 87.02kBTU's delivered heat. SO that's abotu $2.25/100k BTU.

    That's a pretty good savings... good for back-up power and if you care abotu being "green". burning LP or NG directly has a HUGE energy savings over straight electric. You need a COP over about 6 or more to match the carbon footprint of a gas furnace... don't tell the geothermal people that they aren't all that mcuh greener than a gas furnace.

    But in the OP's case, electric is cheaper.

    For emergency use, you can probably get away without heat strips or have the strips install ed on seperate branch circuits so they can be staged, and only run one 5kW curcuit to the back-up panel. Power outages are more common when it;s 25-35F outside, not when there's ice and snow is heavy, than when it's 10F outside.

  4. #4
    Thanks guys. Don't have the heat pump info with me at work. Will get it tonight.

    It seems the heat pump with strips will be more cost efficient, but will it "feel" warm on those cold winter nights? Again, I've never had a heat pump.

    Additionally, if we were to start from scratch, would a HP with strips or the HP w/propane back-up be better for us.

    Thanks! And what an awesome board this is!!!

  5. #5
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,046
    Quote Originally Posted by DougJulie View Post
    Thanks guys. Don't have the heat pump info with me at work. Will get it tonight.

    It seems the heat pump with strips will be more cost efficient, but will it "feel" warm on those cold winter nights? Again, I've never had a heat pump.

    Additionally, if we were to start from scratch, would a HP with strips or the HP w/propane back-up be better for us.

    Thanks! And what an awesome board this is!!!
    If the supply air from your heat pump at 30 degrees outside was 95 degrees and your house would maintain that heat level would you be comfortable, would there be enough heat? A heat pump in your area will work fine if sized and installed properly and the house is energy efficient.

  6. #6
    Join Date
    Sep 2009
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    Arnold mo
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    Quote Originally Posted by DougJulie View Post
    Thanks guys. Don't have the heat pump info with me at work. Will get it tonight.

    It seems the heat pump with strips will be more cost efficient, but will it "feel" warm on those cold winter nights? Again, I've never had a heat pump.

    Additionally, if we were to start from scratch, would a HP with strips or the HP w/propane back-up be better for us.

    Thanks! And what an awesome board this is!!!
    No, heat sprips will be significantly more expensive as compared to that of propane.
    An answer without a question is meaningless.
    Information without understanding is useless.
    You can lead a horse to water............
    http://www.mohomeenergyaudits.com

  7. #7
    Join Date
    Mar 2006
    Location
    The South
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    1,976
    I don't mean to be disagreeable or argumentative but based on OP's rates, the previous post is simply not correct.

    Heat strips alone on a BTU basis compared to propane is much cheaper. Then when a heat pump is added into the equation the operating costs only get better compared to propane.

    For Julie and Doug, you need to decide how important operating costs are to you. Most people who have had nat gas heat will probably not like HP heat. Supply temps from newer HP systems while greatly improved will be less than nat gas, oil, propane heat.

    It should be noted that propane prices track oil prices. also there is a more competitive marketplace for fuel oil, propane, and nat gas compared to the more highly regulated electric utilities.

    Still at this very moment, HP heating with backup heat strips will be much cheaper to operate than a propane furnace. Dual Fuel-HP with propane furnace backup may be an acceptable compromise to your situation. I suggest though that you go through this heating system with the heat pump and then evaluate in the spring.

    I also recommend that HP system have a thorough PM checkup if this has not already been performed.

    I agree with 2nd opinion's comments.

    IMO

  8. #8
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    Sep 2009
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    Arnold mo
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    Sorry about my last post. Based on the rates they posted earlier it does look like I was wrong. I will double check the rates just to be sure. Weird how much of a price difference there is across the USA.
    An answer without a question is meaningless.
    Information without understanding is useless.
    You can lead a horse to water............
    http://www.mohomeenergyaudits.com

  9. #9
    Join Date
    Jan 2008
    Posts
    1,859
    Not really familiar with your climate, but I don't think you'll be using back-up heat very much.
    "Hey Lama, hey, how about a little something, you know, for the effort." And he says, "there won't be any money, but when you die, on your deathbed, you will receive total consciousness." So I got that goin' for me, which is nice. - Carl Spackler

  10. #10
    Join Date
    Jan 2002
    Location
    East Grand Forks, MN
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    1,373

    Perhaps

    Quote Originally Posted by DougJulie View Post
    My question is: Upgrade to new heat pump with electric strips, or make the investment to have a propane backup for low temps?
    Depends.


    We would like to have a back-up generator (propane powered). Relize a 20kw generator would not power the strips..., but could power the propane backup.
    I think you meant a 2kw generator. That's a good idea; do you have power outages occasionally?


    Current Electric Price: 9.037 cents/kwh
    Current Propane Price: $3.50/gal
    Any help is appreciated!
    Thank You!
    Heat pumps with strip heat are excellent heating systems. Very economical compared to propane just about anytime. Up here where I'm at, we highly recommend supplemental heat (strip heat) with HP (especially for economic reasons) with propane as the main fan control and backup heat. Reasons:
    more economical to run: because of lower electric rates (off-peak), and a propane furnace for a backup, because here in the country ( outside the city) you might lose power occasionally. A smaller generator is more cost effective.

  11. #11
    Join Date
    Mar 2008
    Location
    Baltimore MD and Ridgebury PA
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    542
    Quote Originally Posted by DougJulie View Post
    Good Day,

    We just moved into a home in Central Maryland with a Heat Pump w/ electric back-up strips. I have only ever had NG heat. There is no option for NG at the new house. My question is: Upgrade to new heat pump with electric strips, or make the investment to have a propane backup for low temps?

    Additional info:
    Currently no propane tank onsite.
    We would like to have a back-up generator (propane powered). Relize a 20kw generator would not power the strips..., but could power the propane backup.

    Current Electric Price: 9.037 cents/kwh
    Current Propane Price: $3.50/gal

    Any help is appreciated!

    Thank You!
    Are you taking the distribution cost of the electric into account with your posted electric rate? The 9.037 you posted sounds like the supply/generation fee only assuming you have BGE with the same rates as I. You have to take the total cost into account. The easiest way to do this is to take the total of your last bill, subtract the $15 or so they charge for providing service per month, and divide by your total kwHrs used.

    $3.50 sounds like a lot for propane. How many places did you call? What size tank were they estimating? How many gallons per year?

    Quote Originally Posted by DougJulie View Post
    Thanks guys. Don't have the heat pump info with me at work. Will get it tonight.

    It seems the heat pump with strips will be more cost efficient, but will it "feel" warm on those cold winter nights? Again, I've never had a heat pump.

    Additionally, if we were to start from scratch, would a HP with strips or the HP w/propane back-up be better for us.

    Thanks! And what an awesome board this is!!!
    Cost effective and best for you may not be the same. I have a heat pump with oil backup. It was installed well before oil hit $4 a gallon. I may switch to propane backup partly for the benefit of having the ability to get a tankless propane water heater (tankless electric require insane amounts of power), and/or a gas range... not expecting to necessarily save money vs electric.

    Regardless, the heat pump with electric may be the most cost effective but if you don't like the supply temperatures then it may not be right for you anyway. That being said, if you will be installing a generator then yes, it could easily power a furnace as opposed to staging strip heat, though as others point out the heat pump may be able to provide enough heat during an outage anyway. This would depend on your heat load and heat pump size.

    Quote Originally Posted by arc8 View Post
    Depends.




    I think you meant a 2kw generator. That's a good idea; do you have power outages occasionally?




    Heat pumps with strip heat are excellent heating systems. Very economical compared to propane just about anytime. Up here where I'm at, we highly recommend supplemental heat (strip heat) with HP (especially for economic reasons) with propane as the main fan control and backup heat. Reasons:
    more economical to run: because of lower electric rates (off-peak), and a propane furnace for a backup, because here in the country ( outside the city) you might lose power occasionally. A smaller generator is more cost effective.
    I wouldn't be at all surprised if the OP did in fact mean a 20kW generator. I don't think we have installed any generator less than 5kW and most are 10kW or larger. The largest residential generator we have installed was something like 60kW. What a monster.

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